Open clamp structures of the type, for example, illustrated in my prior U.S. Pat. No. 4,299,012 which include a so-called "Oetiker" ear have found widespread use in various applications. In one of these applications, such types of open clamps are used on the assembly line in the automobile industry to fasten axle boots onto axles. For that purpose, open clamps which are already preformed into substantially circular configuration are placed about the axle boots, are manually closed by engagement of the hooks provided on the inner band portion in apertures in the outer band portion and are thereafter fastened by contraction of the so-called "Oetiker" ear.
It is also known to ship open clamp structures to the user as flat blanks to benefit from the space- and cost-saving advantage which may be as high as 18:1 compared to the cost of transporting already circularly deformed clamps and to deform the flat blanks into a predetermined shape at the user. My prior U.S. Pat. Nos. 4,633,698 and 4,425,789 disclose machines for preforming the flat blanks at the user.
The manual operations involved heretofore required four persons at the assembly line before the installation of the clamps on the axle boots was completed. Because of human errors, a fifth person was normally present to control for proper installation of the clamp and a sixth person had to be available to remove improperly installed clamps and correct the deficiencies noticed by the control person by installing another clamp in its place. Thus, the prior art method for installing these clamps was relatively labor-intensive. Additionally, the waste was relatively high because the improperly installed clamp structures had to be destroyed in order to remove the same and thus became useless scrap. Apart from normal human errors, the problems in the prior art method were further compounded by lack of uniformity in the installation of the clamps, not only due to improper application of the pincer-like pneumatic tool closing the so-called "Oetiker" ear but also by vastly varying actuation of the pneumatic tool, which in turn resulted in closing of the ear at different speeds and with greatly differing forces. However, for metallurgical reasons, an excessively rapid deformation of the ear and/or excessive closing forces may affect the quality of installation of the installed clamp and its holding ability.
Thus, the prior art method as described above, which has been used on the assembly line in the automotive industry, entails numerous problems which not only affect cost, but also quality of the installation of the clamp on the axle boot and therewith the length of life of the axle assembly intended to retain in an absolutely tight manner the lubricant present on the inside of the axle boot.
My prior copending application Ser. No. 016,794, filed on Feb. 20, 1987, and entitled "Apparatus and Method for Automatically Installing and Fastening Clamps Onto Objects To Be Fastened" addressed these problems and described an apparatus and method for automatically installing clamps which far-reachingly eliminated the aforementioned shortcomings and drawbacks encountered in the prior art and assured a foolproof installation of the clamp structure, independent of human errors. According to the method and apparatus disclosed in my prior copending application, the subject matter of which is incorporated herein by reference, this is achieved by deformation of a flat blank into a circular shape, closing of the clamp, automatically transferring the closed clamp from a deformation station to a transfer station where the clamp is placed over the axle boot, holding the clamp in proper position on the axle boot by frictional engagement of the previously slightly deformed clamp, and thereafter contracting the ear in the thus-installed clamp to tighten the clamp structure about the axle boot and thus hold the latter tightly on the axle itself. According to my aforementioned copending application, the clamp is so mounted over the axle boot at the transfer station that it will stay in predetermined position while the axle, axle boot and clamp assembly thus-assembled is moved from the transfer station to the fastening station so as to assure that the pneumatic pincer-like tool closes the ear each time in a completely satisfactory manner owing to the relative fixed position between the ear and the pneumatic tool. The circular clamp, picked-up at the deformation station is thereby plastically deformed into slightly non-circular, oval shape and before being placed over the axle boot, is again elastically deformed back into circular shape so that upon release of the gripping fingers, the clamp will seek to return to its slightly non-circular configuration to produce a frictional engagement between the clamp and the axle boot keeping the ear in a predetermined position until it is engaged by the pneumatic pincer-like tool.
However, the apparatus and method according to my aforementioned application still required a person to insert the flat blank into the machine at the deformation station by manually picking up individual flat blanks, as shipped, from boxes that contained several bundles of 100 or more such flat blanks.
Drum-type devices are known in the art for feeding or dispensing various items, such as nails (U.S. Pat. No. 1,132,683), pencils (U.S. Pat. No. 1,853,071), phonograph needles (U.S. Pat. No. 1,412,826) or cores for cop-winding machines (U.S. Pat. No. 2,843,509). However, none of these prior art devices are suitable for the present invention which involves separating individual, relatively thin elongated and flat clamp blanks from a large supply thereof by positively gripping the blank to be lifted to its release point above the other blanks in the supply which remain at the bottom in the rotating drum as a result of gravity. Furthermore, machines for applying clamps are known in the art, for example, as disclosed in U.S. Pat. No. 2,837,949. However, these prior art machines require manual operating steps necessitating the presence of operating personnel.